Effects of penicillamine on distribution of B6 vitamers in rat urine.

Abstract
The antivitamin B6 effect of DL- and D-penicillamine was studied in rats. A considerable elevation in the urinary excretion of vitamin B6 activity (pyridoxal and its thiazolidine derivative) was a parameter of B6 antagonism. Both DL- and D-penicillamine had an antivitamin B6 effect in rats, although that induced by the DL-form is considerably greater, as would be expected from previous studies. B6 supplementation should be included in any long-term penicillamine therapy, regardless of the isomer that is employed.